VCs see a tiny chance that it can be a 100X return. So raising $20M at say a $50-100M valuation now, that means betting on a $5B+ exit. In return for getting money to take a shot at that level of artificially-fueled revenue growth, the founders are willing to cede control of the community to professional financiers. As others wrote, that's the VC model: make a ton of these bets, and as long as 2-4 turn out, the lottery winners pay for the bankruptcies.
Given every big company uses JS, and thus many SaaS VCs have JS in their annual set of thesis bets, it's reasonable that Deno got picked by a top group given their team & growth. Same story with npm, netlify, etc.
I wish the team luck in hitting significant revenue in the next 9-12mo, as that will determine a lot of what happens to the community. A lot of pressure & culture change to work through!
The main base expectations are that out of all of Sequoias bets, some will become $5B+ co's, and for the next 18mo, deno can grow headcount with salaries unrelated to sustainability
Some people involved might expect more, and I'm sure hope for more, but I'm a language designer & CEO, not a mind reader :)